Crimp tool and dies



Feb. 11, 1964 H. H. ESSER CRIMP TOOL AND DIES Filed May 29, 1961 I N V EN TOR. /Vm// [554);

30 ank [far/W United States Patent 3,120,773 CRIMP TOOL AND DIES Harold H. Esser, Chicago, Ill., assignor to Ideal Industries, Inc., Sycamore, 111., a corporation of Delaware Filed May 29, 1961, Ser. No. 113,332 3 Claims. (Cl. 81-15) This invention is in the field of electricians pliers and is concerned with a tool for crimping electrical connections as well as other conventional functions normally associated with electricians pliers.

A primary object of my invention is electricians pliers having crimping dies arranged for increased mechanical advantage so that the pliers may be used with a larger number of crimp sleeve sizes.

Another object is electricians pliers which have double crimping dies, one the reverse of the other, with the recess of one cooperating with the crown of the other.

Another object is electricians pliers of the above type Where a part of the crown of one crimp is a part of the recess of the other.

Another object is electricians pliers of the above type constructed to accurately determine maximum penetration of the crimping dies.

Another object is electricians pliers with crimping dies arranged so that standard wrench handles will apply sufficient leverage.

Other objects will appear from time to time in the ensuing specification and drawings in which:

FIGURE 1 is a side view of electricians pliers embodying my invention;

FIGURE 2 is a top view of FIGURE 1;

FIGURE 3 is a side view, on an enlarged scale, of the head portion of the pliers;

FIGURE 4 is a section along line 44 of FIGURE 3;

FIGURE 5 is a section along line 55 of FIGURE 3; and

FIGURE 6 is an enlarged view of the pivot and knife edges.

In FIGURE 1, electricians pliers have been indicated generally at 10 and include two main levers 12 and 14 each of which has handles 16 and 18 on one side of a pivot 20 and jaws 22 and 24 on the other in a conventional manner. The pivot 20 may be of any suitable pivot structure and I have not shown it in detail. The lever structure around the pivot and each side thereof may be of the usual overlapping type and the details of the handles themselves are not important, except as mentioned hereinafter.

Forward of the jaws, I position gripping surfaces 26 and 28 which may be of the usual serrated type, note FIGURES 4 and 5.

Just behind the gripping surfaces but ahead of the pivot, I position crimping dies, 30 on the lower jaw and 32 on the upper jaw. The dies themselves are adapted to crimp a ferrule or sleeve, terminal or otherwise, on the stripped ends of electric wires. Such a crimp connection is old and well known and, basically, involves positioning the stripped ends of two or more electric wires inside of a ferrule or sleeve and then crimping the sleeve down on the wire ends. Reference is made to US. Patent No. 2,810,897, issued October 22, 1957.

I construct the crimping jaws with two crimps, each including a projecting crown which sockets into a concave recess, but one is the reverse of the other. For example, in FIGURE 3 I position a crown 34 on one jaw somewhat closer to the pivot than a concave or recess 36 next to it. On the other jaw, the recess 38 is somewhat closer to the pivot than the projecting crown 40 next to it. It will be noted that the crown 34 on the lower jaw cooperates with the recess 38, these being 3,120,773 Patented Feb. 11, 1964 closest to the pivot and somewhat larger than the crown 40 which cooperates with the recess 36. I thus position the crown and recess which require the greatest force next to the pivot, whereas the somewhat smaller crown and recess are more remote and have a somewhat longer lever arm. It will be noted that by making one the opposite of the other, the surface of one flows smoothly into the surface of the other.

For example, considering the lower dies: 30 in FIG- URE 3, the arcuate crown surface 42 flows smoothly and nninterruptedly into the recessed surface 44 of the concave. When the jaws are closed, as shown in FIG- URE 1, the opening defined between the jaws takes on a figure S appearance. The advantage of reversing the dies instead of putting both crowns on one jaw and both recesses on the other is that the dies can be much closer together. Therefore, dies 36 and 40 can be closer to the pivot, thereby having a greater mechanical advantage.

I specifically construct or proportion the dies so that the inner set 34 and 38 handles a certain range of sleeves, the larger sizes, while the outer set 36 and 40 handles a second range, the smaller sleeves.

I provide abutting or flat surfaces 46 and 48 between the die sets and the gripping surfaces which contact, when the jaws are closed, as shown in FIGURE 1, to determine the maximum excursion of each crown into its opposed recess. Thus, I insure accurate crimping of the sleeves and the degree of penetration is not left to mere chance.

On the other side of the pivot 20 I may position two shear type cutting edges 50 and 52 which are offset from the center plane 54 by a certain angle, designated at 56, the angle being such that the knife edges 58 and 60, when extended toward the center 62 of the pivot, would be tangent to an imaginary circle 63. In effect, each knife edge, when extended, would pass behind the pivot center. The imaginary circle 63 would have a diameter equal to the diameter of the maximum intended wire size. Thus, when the maximum wire size was to be cut, the knife edges 58 and 60 would be approximately par allel when they first contacted the wire. When cutting smaller wires, the edges 58 and 60 would be at a small angle opening inwardly toward the pivot center so that any extruding effect would be inward instead of outward.

It will be noted in FIGURES 4 and 5 that the sides of the jaw surfaces, laterally opposite the crowns and recesses, are recessed or relieved, as at 64, so that the ends of solid or stranded wires are allowed to flare. Also, the ends of the crimping sleeves may flare into this recessed area ,as set forth in US. Patent 2,731,862, issued January 24, 1956.

The use, operation and function of my invention are as follows:

I provide crimping dies on conventional electricians pliers with the dies being constructed to accommodate a wide range of sleeve sizes. I position the dies reversed or back to back so that one pair is the opposite of the other. Thus, the surface of each crown flows smoothly into the surface of its adjacent recess. This allows the dies to be positioned closer together, and both are that much closer to the pivot. This is particularly important for the outer dies, shown in this case as the smaller set 36 and 40, since they would otherwise be several hundredths of an inch farther away from the pivot and with just that much less mechanical advantage. This would reduce the number of sleeve sizes the dies would accommodate. But by turning one set around so that together they define an S shape between them, both are closer to the pivot, the mechanical advantage is increased, and the range of sleeve sizes is increased.

The knife edge shearing blades have the advantage that wire will not be extruded or forced outwardly from between them, since they come together, when contacting a wire, on a plane more or less normal to the wire, or possibly with a small amount of reverse rake.

While I have shown and described the preferred form of my invention, it should be understood that suitable ad? ditional modifications, changes, alterations and substitutions may be made. For example, I have shown the crimping dies on the jaw side of the pivot and the shear or cutting blades on the handle side. But it should be understood that in certain circumstances they may be reversed, With these and other modifications in mind, I wish that my invention be unrestricted, except as by the appended claims.

I claim:

1. In a pair of ,electricians pliers,

two members connected near one end by an axially fixed pivot with jaw portions on one side of the pivot and elongated handle portions on the other side of the pivot,

opposed die surfaces adjacent the pivot adapted to coact with one another on manipulation of the handle portions to effect a crimping action when a member to be crimped is positioned between them,

each die surface including a crown projecting somewhat from the surface next to a concave recess in the sur- 25 face, the crown and recess on each die surface being longi tudinally next to each other with one flowing into he o her,

the recess on one jaw portion being of a different size from the recess on theother jaw position,

each crown being appropriately contoured to cooperate with its associated recess,

the crown and recess on one jaw portion being reversed relative to the crown and recess on the other jaw portion so that the crown on one jaw portion is opposite the recess on the other jaw portion, and vice versa.

2. The structture of claim 1 further characterized by and including abutting surfaces on at least one side of the die surfaces longitudinally thereof adapted to contact to determine the maximum penetration of the recesses when the jaws are fully closed 3, The structure of claim 1 further characterized by and including a lateral recess adjacent each of the projecting crowns to allow for flaring of the ends of electric wires and the crimped member during the latter portion 20 of the crimping operation.

References Cited in the file of this patent UNITED STATES PATENTS 2,583,625 Bergan Jan. 29, 1952 2,731,862 Schinske Jan, 24, 1956 2,979,085 Rogge Apr. 11, 1961 

1. IN A PAIR OF ELECTRICIAN''S PLIERS, TWO MEMBERS CONNECTED NEAR ONE END BY AN AXIALLY FIXED PIVOT WITH JAW PORTIONS ON ONE SIDE OF THE PIVOT AND ELONGATED HANDLE PORTIONS ON THE OTHER SIDE OF THE PIVOT, OPPOSED DIE SURFACES ADJACENT THE PIVOT ADAPTED TO COACT WITH ONE ANOTHER ON MANIPULATION OF THE HANDLE PORTIONS TO EFFECT A CRIMPING ACTION WHEN A MEMBER TO BE CRIMPED IS POSITIONED BETWEEN THEM, EACH DIE SURFACE INCLUDING A CROWN PROJECTING SOMEWHAT FROM THE SURFACE NEXT TO A CONCAVE RECESS IN THE SURFACE, THE CROWN AND RECESS ON EACH DIE SURFACE BEING LONGITUDINALLY NEXT TO EACH OTHER WITH ONE FLOWING INTO THE OTHER, THE RECESS ON ONE JAW PORTION BEING OF A DIFFERENT SIZE FROM THE RECESS ON THE OTHER JAW POSITION, EACH CROWN BEING APPROPRIATELY CONTOURED TO COOPERATE WITH ITS ASSOCIATED RECESS, THE CROWN AND RECESS ON ONE JAW PORTION BEING REVERSED RELATIVE TO THE CROWN AND RECESS ON THE OTHER JAW PORTION SO THAT THE CROWN ON ONE JAW PORTION IS OPPOSITE THE RECESS ON THE OTHER JAW PORTION, AND VICE VERSA. 